---------------------------------------------------------------------------------------------------------------------------------------------- Airships have received a lot of attention in recent years, for both the transport of passengers and goods. They are more economical and silent than airplanes, and they are still considerably faster than most means of transportation over land or water. That said, zeppelins are faced with some problems.

To stay afloat they use helium, a non-renewable gas becoming scarce. Moreover, because of their round shape and insignificant weight they are hard to manage when they are on the ground. They also need a significant amount of parking space, making the hangars more expensive than the airships themselves.

Lieven Standaert, a Belgian engineer, architect and science teacher, plans to build a zeppelin that holds none of those disadvantages. His Aeromodeller II is inspired by the zeppelin of the same name built in 1970 by his compatriot, the legendary artist Panamarenko.

Panamarenko is devoted to building fantastic flying machines that have never flown (although he maintains that they do). Lieven Standaert, on the other hand, is determined to actually fly his dream machine. An exhibition currently running in Antwerp is largely dedicated to the low-tech and low-cost techniques to develop this "yacht of the 21st century".

Enjoy the view

The Aeromodeller II floats not on helium but on hydrogen, which has a dual function as fuel for the engines. The hydrogen is generated on board, while the ship hovers in the air and drops anchor at a height of 50 to 100 metres. This happens by means of a cable, similar to that of a kite.

The zeppelin inverts its propellers, which then serve as windmills. They deliver the necessary energy to split water (coming from the ballast tanks and replenished by rain) into hydrogen and oxygen. Six hours of wind energy accumulate enough fuel for one hour of flying.

This means that the airship has to “rest” regularly to charge its “batteries” – just like a living creature. This would be the perfect moment to slide open the large windows, take a seat on the terrace and enjoy the sun and the view.

Worldwide autonomy

Standaert’s solution to the ground manageability problem and the need for a specially designed airport and energy infrastructure is rather radical: he wants to keep his zeppelin in the air. Because the Aeromodeller II generates its own energy, it never has to land.

This implies that the airship should be regarded as a houseboat or stray ship and not as an alternative to a scheduled flight. The Aeromodeller II is designed for stability and not for speed. While other airships can attain speeds of up to 150 km/h (93mph), the Aeromodeller with its two 70 kilowatt engines will only reach speeds of about 80 km/h (50mph).

Yacht

Lieven Standaert: "Airships are slow. You don’t design a good vehicle starting from its weaknesses. Forget speed. This thing can never be a good speedboat. It is a sailing ship. Make it storm proof. Make it seaworthy. We love sailing ships, not for their speed or efficiency, but because of the way of travelling. A zeppelin can be worthwhile in a similar fashion. You can get on board with a backpack full of biscuits and canned soup and just take off, without the need for petrol stations or anything. You can re-appear two years later, coming from the other direction..."

Hydrogen flagship

Floating around in a zeppelin for a couple of years will not appeal to everybody, whether the airship has a sun terrace or not. What Standaert desires to accomplish with his project is to promote hydrogen as a clean fuel. A zeppelin is better suited for that than a car:

"Cars are not the best vehicle to demonstrate the potential of hydrogen. BMW has a car on display in Brussels that drives on hydrogen. But as long as we have not 1,000 hydrogen stations across Europe this car cannot drive anywhere. And these hydrogen stations will only appear when everybody is convinced that hydrogen is the best substitute to gasoline."

"My airship has to become a symbol, a flagship for cleaner energy technology. Because it generates its own energy, it needs no new energy infrastructure. Because it does this by means of wind energy, it is a real zero-emission vehicle. And the space required for the storage of hydrogen, the most important practical problem for the use of hydrogen in cars, is not a problem in a zeppelin of 85 meters either."

Historical trauma

Hydrogen and airships are not a self-evident combination. Lieven Standaert: “Zeppelins bear a historical trauma. In 1937 the Hindenburg burned down and since then all airships are filled with non flammable helium. But, if we can develop safe hydrogen cars, we can develop safe hydrogen zeppelins. There are still engineers speculating on how the fire started in the Hindenburg. Don’t speculate, perform the tests.”

“Nobody has published anything on experiments with hydrogen balloons in the last 50 years. Adisson Bain, a NASA-engineer, is one of the authorities on the Hindenburg disaster. His experiments consist of fire experiments on pieces of skin measuring 10 by 10 centimetres. But there is no way you can scale down fire experiments like that, a match does not burn in a similar fashion as a forest. I have done these experiments on a reasonable scale, and the results have convinced me that I can build a safe ship.”

Castle in the air

You seem to be convinced that you can realise this airship. Many of these projects have never gotten further than paper or scale models…

Lieven Standaert: "Zeppelins are the ultimate castles in the air, every few years a concept for another type of airship comes along. Some 5 years ago it was the Cargolifter, a gigantic project in Germany to design a zeppelin with a length of 250 metres. The idea was to pick up anything that was too large for conventional road transport and put it down 500 kilometres further."

"In Germany zeppelins are still the stuff of legends, so they received serious funding. They built a huge hangar and they put 80 engineers in there to find out how to realise this thing. But while the engineers were calculating, they passed their deadline by 2 years, they had enormous overheads, and they went broke. The hangar was built, and it is the largest one in Europe. The ship, however, was never realized.”

How are you going to avoid a similar scenario?

"From the start, my ship was designed to be built with low-tech and low-cost building materials. Conventional airships have the form of a cigar, which is realised by overpressure inside the ship. This enables a light construction and a fast aerodynamic shape, aimed at speed. However, this kind of construction is very vulnerable, because the skin is an essential part of the construction."

"If there is a leak, the ship loses overpressure suddenly, it loses its shape and it loses all control. And with a round belly like this, a zeppelin is completely unmanageable on the ground: several airships were damaged irreparably because a blast of wind smashed them against the hangar."

Low-tech

“My design does not need overpressure to preserve a stable form, which means that the forces on the skin become much smaller. The Aeromodeller has a wide frame which absorbs these bending forces. This makes the zeppelin heavier and slower than other airships, but it also makes it sturdier, and much easier and cheaper to build. You don’t need a woven skin material. A light thermoplastic foil will suffice.

"If you want to accomplish such a high-flying project, you have to think very practical. An important part of the exhibition deals with the question of how to build this thing with 3 people, cheap materials and a flat-iron."

"The full explanation is a bit more complex, of course, but this is the essence. Focus on the design to build a functioning prototype with modest means. Invest your money in the prototype, not in a hangar. Keep your overheads low, so that you can carry out experiments. Make sure you don’t need scaffolding or high cranes, but design it so that you can build it on ground level. And then, technologically speaking, this is just a gigantic, ultralight tent. Then you have something that you can rig up for the price of a large house."

The aeromodeller's advantages are that it doesn't need to land, it refuels itself, and is self-regenerating. These are advantages from the classic zepplin model in the fact that Hydrogen is a superior lifting gas, and is far more abundant than helium, and with a Nitrogen buffer between the Hydrogen and the Air outside, the chance of the Hydrogen becoming flamable is significantly decreased. With the use of Hydrogen, the baseship can be smaller yet lift bigger loads.

Hydrogen is only marginally superior as a lifting gas- you get an extra 5lbs of displacement per 1000cu ft.
That said, the dangers of hydrogen are not nearly as bad as commonly assumed. Fatalities in observational balloons were low during WW1, even though pilots were floating in hydrogen balloons and being shot at with incendiary rounds. Its surprisingly hard to light a hydrogen balloon on fire.

While I would not feel very comfortable close to large amounts of hydrogen held by thermoplastic foil (or inside a composite high-pressure tank, for that matter), it seems to be true that Hindenburg catastrophe had little to do with its choice of buoyancy gas: fire was stated by sparks generated by static electricity (the ship was not properly grounded before being allowed to touch the mooring mast) seting fire to resin coating the envelope, not any leaking hydrogen.

You cannot make a hydrogen-bag airship and not have a fire risk! The "hydrogen" under development cars carry far smaller amounts of H, in high pressure steel canisters with a matrix inside. No way am I getting inside a hydrogen balloon!

"The Aeromodeller has a wide frame which absorbs these bending forces. "
Zeppelins such as the Hindenburg, DO have a support frame under the canvas cover.

You could also collect energy via ionospheric resonance, solar power or dedicated "refueling stations" which would appear as tall rods. Even just using solar (I did the surface area calculation according to the 1.7m human in your drawing) you could extend the runtime of your vehicle anywhere from two to five times (depending on future solar cell development)
Your trip would still be limited by how much food and water you can carry, perhaps some sort of collection mechanism for rainwater as well as fishing equipment?

I'm worried about the shape though, this is pretty radical for a zeppelin. Are you sure it stands up to scrutiny?

As this thing is supposed to fly above the clouds you'll have a hard time capturing a rainstorm. If you want to do that you'll have a hell of a bumpy ride.
On the drawing at the beginning of the article there is the following to read:
"Planes need a pressurised cockpit, balloons don't! Get a good scarf!"
Actually you do need a pressurised cockpit in a balloon, our at least some kind of oxygen mask. You need one once you start to camp at higher altitude for a longer time even when mountaineering, And if you want to camp in the sky these are the altitudes where you will reside.
I'm not going to talk about the capital error about the Zeppelins keeping form trough over pressure, someone else already did.
As Reto said before:"Another fantastic article! The drawings seem to come right out of a futuristic alternative world comic..."
That's exactly what it is; the fantastic 30's - 40's comics fuelled idea! Just add some kind of Dr Evil or Professor X and the story is complete.
The whole thing is pathetic!

the way its operation is explained is like hearing it from a 3 year olds imagination, im not going to bother posting the nails in the coffins. if your going to show me a concept, SHOW ME ONE THAT CAN ACTUALLY WORK IN THE REAL WORLD. really idealistic though

Go for it! Flying was impossible before the first airballoon and airplanes took off and look now?! It is 'normal' and a billion dollar industry. If some large companies would research anything that hasn't researched enough yet for 10-20yrs it will become 'normal' too. Its the public mind/vision not the technolgy that is the barrier, just take a close look at our species history...

first of all, things break down and wear out and im sure this will break down and ect all of the time. it would be a complete waist of money to ride arround the world little none to find the parts to fix it. What happens if you get a spot on it from the sun and that spot eventually wears into a hole, how do u propose to fix that? all in all its just a big waist of time money and effort.

It's waste, not waist.
Things breaking is not an argument, everything will eventually break.
The article states clearly, that these ships are built for ease of building and the use of abundant resources.
So maintenance should be relatively trivial.

Cars are an even bigger waste of time, effort and money, but everyone wants two.

i was thinking of something like this a long time ago, my idea was to have a light steel frame, like wire hoops, cables attaching them to a hoop on the outside of plastic mesh sheets. the hydrogen bags would have been plastic tubes, mesh bulkheads would be used in case some of the lift cells had to be deflated for maintenance, easy to get, easy to recycle, uncut heavy duty garbage bags. they'd look a lot like intestines... they'd be melted closed at the ends, have a bung and tubing on an end, some tabs glued on, in case the shell ripped, they wouldn't get lost, though they'd look like a tentacled horror while returning to ground for repairs.
an oblong hoop and cables down the middle to set the overall shape, with mesh there, so cells could be worked on each side. the inner frame could be any shape, and relatively easy to attach the 'home' to.
i probably would have used very light nylon mesh or kevlar over the whole thing, inflated and sprayed from the inside with epoxy to harden it into aerodynamic shape, before the lift cells and inner mesh was put in. being aerodynamic would at least mean the engines wouldn't have to work as hard to overcome a wind... the idea of a nitrogen buffer is good, the outer shell could be filled with it, and oxygen concentrators/nitrogen extractors can use non-clumping kitty litter as a molecular sieve, at a low enough pressure that building it from cheap pvc pipe is an attractive prospect, would also work to keep the air inside fresh, it could also be charged by foot pump, in electrical emergencies.

I don't know if the scenario given is feasible or not, but this is a terrible shape for such a creation. It's well known that, if you're striving for the least drag for a given volume, the larger that volume, the stubbier the best shape is. That's good, because a stubbier shape can also be much LIGHTER for the volume and/or much stronger. That reduces material required to build it, the amount of hydrogen to fill it, the power required to make it go, and therefore the total cost. See the URL below for a paper about optimal shapes for airships. The one shown here is probably about right for something 5 or 10 feet long, or perhaps even less.

The advantage of lower structural weight is very important. If this source is to be believed, the Hindnburg had about 7 million cubic feet of volume. Using hydrogen for buoyancy, that translates to about 500,000 lbs of weight, not counting the weight of the hydrogen. Yet the useful load is listed as only 22,000 lbs! That leaves something like 480,000 lbs of structure, engines, and material to enclose the gas. Anything that reduces the amount of structure, enclosure, and power required (see paper below) will make the airship much smaller and cheaper. For instance, if you go to a shape that's 2 1/2 times as long as the diameter,and I've done my calculations right, for a given volume the exterior envelope will have only about 60 percent as much area. Savings in structural weight will be even greater, at least proportionally. As per the paper, drag will be much lower.

Drag is very important, because in order to survive, this airship will need to outrun the weather. (It will also have to stay out of places where thunderstorms build up quickly.) Lower drag also means lower mooring forces. It also means that, if you keep your recharging turbines close to the hull, they can be smaller on the fatter hull, because the air is accelerated more to get around it. If we're go 50 mph, I think the Reynolds number on the optimized shape is going to be around 1.1 x 10^7. See figure 9 in the paper. Perhaps an even stubbier shape may be optimal if we use the propulsion to control the boundary layer and pressure recovery as seen in the papers of Goldschmeid**.(I sdmit I find those papers heavy sledding.

As far as using overpressure structurally, how can you resist a structural element that is lighter than air? You wouldn't necessarily have to pressurize the whole envelope. It might make more sense to use tubes at several atmospheres of pressure as large beams. A further advantage is that if you really can't outrun a storm, you can land and deflate. Expensive to refill, but not as bad as losing the airship and maybe your life.

I'd like to see a more technically correct evaluation of the scenario. Maybe there's something that would work. Whether it would fit in with culture, politics, and regulation is another question entirely.

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